Picture frame



FIG. 1 is a perspective view of a picture frame showing my new design;

FIG. 2 is a reduced side elevational view taken from the left of FIG. 1;

FIG. 3 is a top plan view thereof;

FIG. 4 is bottom plan view thereof;

FIG. 5 is a rear elevational view thereof; and

FIG. 6 is a front elevational view thereof. 

The ornamental design for a picture frame, as shown and described. 